Integrated Circuit Backside Power Delivery Using Self-Aligned Source/Drain
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Solution Overview
Problem
Integrated circuit devices with power delivery networks on the backside face manufacturing complexity and reliability challenges due to complex structures and processes.
Innovation Solution
A method of manufacturing integrated circuit devices involving the formation of a first etch stop layer, self-aligned source/drain regions, and a base dielectric layer, with a rear conductive line connected to the source/drain region, to simplify the manufacturing process and enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a power delivery network is formed on the backside of integrated circuit devices, then power delivery efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
Place holders are formed in advance at the front side before substrate removal, preparing the structural framework needed for backside power delivery network formation. This preliminary action simplifies subsequent manufacturing steps by having critical structures ready before the device is flipped for backside processing.
Solution Approach 2:
The place holders act as intermediary structures that facilitate the complex backside power delivery network formation. These temporary structures guide the self-aligned formation of source/drain regions and enable reliable electrical connections without requiring complex alignment processes during backside manufacturing.
2Manufacturing precision
If self-aligned source/drain regions are formed with place holders, then manufacturing precision is improved, but device structure becomes more complex
Solution Approach 1:
The place holders enable self-aligned formation of source/drain regions through selective epitaxial growth. The source/drain regions automatically align with the place holder structures during the epitaxial process, eliminating the need for complex photolithography alignment steps and achieving high precision automatically.
Solution Approach 2:
Replace mechanical alignment processes (photolithography and patterning) with a self-aligned epitaxial growth process. The physical structure of the place holders directly defines the position of source/drain regions through material growth, substituting complex mechanical alignment with a simpler chemical vapor deposition process.
3Reliability
If the substrate is completely removed to form backside power delivery network, then power delivery efficiency is improved, but manufacturing difficulty increases
Solution Approach 1:
The place holders are formed in advance at the front side before substrate removal. These pre-formed structures remain intact during the substrate removal process, providing structural support and defining the final configuration of power delivery contacts, thereby simplifying the substrate removal operation.
Solution Approach 2:
The place holders serve as intermediary structures that mediate between the substrate removal process and the final backside power delivery network. They protect critical areas during substrate removal and guide the formation of power delivery contacts, making the overall process more manageable and reliable.
Data Source
AI summary
A method of manufacturing an integrated circuit device may include forming a first etch stop layer on a first face of a substrate; forming a gate structure including a gate electrode layer and first and second source/drain regions on the first etch stop layer, the first and second source/drain regions respectively being self-aligned with opposing side walls of the gate structure and lower portions of the first and second source/drain regions respectively contacting first and second place holders extending into the substrate; removing the substrate until the first etch stop layer is exposed from a second face of the substrate while the first and second place holders are exposed; forming a base dielectric layer on a rear side of the first and second place holders; and forming a rear conductive line may be electrically connected to the second source/drain region.